Device for aligning a stencil in duplicating machines



March 28, 1967 ZIEUTHEN DEVICE FOR ALIGNING A STENCIL IN DUPLICATING MACHINES Filed May 28, 1964 INVENTOR ATTORNEYS United States Patent 3,311,052 DEVICE FOR ALIGNING A STENCIL IN DUPLICATING MACHINES Karl Gustav Zeuthen, Gentofte, Denmark, assignor to Zeuthen & Aagaard A/S, Glostrup, Denmark, a company of Denmark Filed May 28, 1964, Ser. No. 370,774

Claims priority, application Denmark, June 4, 1963,

2,651/ 63 2 Claims. (Cl. 101-116) The invention relates to a device in a duplicating machine for aligning a stencil placed on an ink-penetrable underlay, which, when placed flat, is substantially rectangular, a so-called ink cloth, e.g. a silk gauze, so that the typed lines will be printed parallel to the edge of the paper irrespective whether the typed lines are slanting on the stencil.

It is known to perform an alignment of a stencil by turning the head of the stencil after the latter has been mounted on the ink cloth, so that the upper portion of the stencil is turned a little. By rotating the stencil a few times and possibly smoothing the stencil by hand one may make it lie slightly obliquely on the ink cloth, as during the motion it will slide on the ink with which the ink cloth has been inked. Such an adjustment will, however, require a certain knack to prevent the stencil from crumpling and to prevent smearing.

It is an object of the invention to provide a construction in which the said drawbacks have been remedied, and the device according to the invention is characterized by means for mounting the ink cloth turnably in such a way that together with the stencil mounted on the ink cloth it can be turned, so that the parallel edges of the ends of the ink cloth facing each other will substantially preserve their parallelism when turned into an oblique position. This construction offers the advantage that the stencil after being mounted need not be displaced in relation to the ink cloth with the drawbacks deriving therefrom. It furthermore becomes easy to perform the adjustment without any risk of smearing. 7

It is convenient that the centre of the turning movement of the ink cloth lies approximately in the centre of the ink cloth. Hereby the maximum width displacement of the ink cloth is achieved by the slightest possible turning movement.

According to the invention it is possible to perform a positive control of the ink cloth along both end edges facing each other, but a particularly simple construction is obtained when according to the invention only one strengthened end is provided with means for positively controlling this end, while at the other strengthened end the ink cloth is stressed centrally by a force for stretching the cloth. When one permits the point of attack of the force to be displaced transversely, the ink cloth can be made to adjust itself in the taut and smooth state.

In an advantagous embodiment of the device according to the invention the ink cloth is at one end provided with guiding and carrying pins which fit into slots in a transverse carrying bar mounted on the stencil carrier, said slots having such a form that when moved the edge of said end is forced to perform a turning preferably around the centre of the ink cloth, :and the ink cloth is furthermore at its other end provided with a preferably resilient connecting member which can be connected to a preferably displaceable and turnable member mounted on the carrying bar. The member is conveniently a hook-shaped member with a pin with which the member engages a slot in the carrying bar, while the resilient connecting link is a spring wire which at its ends is secured to the strengthened end of the ink cloth and which at its middle 3,31 1,052 Patented Mar. 28, 1967 is provided with a preferably V-shaped bight which the hook-shaped member can engage.

The adjustment can be effected in a simple way when according to the invention there is mounted on the transverse carrying bar a rotatable adjustment member which engages a pin at one end of the ink cloth and on the hook member, respectively, so that a turning of the adjustment member will entail a displacement of the said pins to opposite sides of a longitudinal central line through the axis of rotation of the adjustment member. Locking members are expediently provided in connection with the adjustment member so that the latter can be locked in a position in which it is set. It is for example possible to use a ball lock or other locking means for stepwise adjustment. A continuous adjustment with clamping in the particular adjusted position may also be used.

The invention will in the following be further explained with reference to the purely diagrammatical drawing where FIG. 1 shows an ink cloth in its spread-out state,

FIG. 2 shows on a larger scale the two ends facing each other of an ink cloth mounted on the rollers of'a duplicating machine, .and'

FIG. 3 shows on a larger scale a section on line III-III in FIG. 2.

FIG. 1 illustrates the principles of the invention and shows a rectangular ink cloth 1, the central part 2 of which consists of an ink-penetr-able material, e.g. silk gauze, which at its ends is connected to strips 3 and 4 of some other material, eg plastic or artificial rubber strengthened with fabric or some other suitable material. The connection may be effected by welding, vulcanization, glueing, or any other suitable method of connection. The end rims 5 and 5' of the ink cloth are strengthened with a sutiable material. One strengthened end rim 5 carries pins 6, 7 and 8 which engage slots 9, 10, and 11 in a carrying bar 12 which is mounted on the stencil carrier, known per se, of the duplicating machine, which stencil carrier usually consists of two bands which are spaced from each other and the motion of which is synchronized with the pressure roller in the duplicating machine. The said synchronization is comprised by the known technique and therefore need not be further described here. At the lower end rim 5' of the ink cloth shown in FIG. 1 a connecting member 13 is secured which is stressed by a force in the direction indicated by the arrow A so that the ink cloth is stretched.

In the position shown in FIG. 1 the ink cloth is shown turned an angle around its point of rotation 0, so that a typed line indicated by the dotted line L which is oblique on a stencil placed on the ink cloth will be placed correctly, viz. at right angles to the central line M through the point of rotation 0.

FIG. 2 shows the construction in some more detail. The two rollers, around which the ink cloth is laid, are designated by 14 and 15. The roller 14 is the pressure roller of the duplicating machine. 16 designates a band which forms part of the stencil carrier of the duplicating machine. On the said carrier a transverse carrying bar 17 is mounted in which the slots 9, 10, and 11 mentioned above are provided. The latter is not shown in FIG. 2. The slots are circular-arc-sh-aped preferably with their centres in the middle 0 of the ink cloth. At one end the slots have an enlarged part so that an enlarged head on the pins 6, 7, and 8 can be led into the slots.

The carrying bar 17 is furthermore provided with a slot 18 for receiving a pin 19 on a hook-shaped member 20 which with its hook-shaped part engages a V-shaped part of the connecting member 13 which is secured to the strengthened end rim 5' of the ink cloth.

' the figure.

The stencil is hooked on to pins under an openable carrying bar 21, but the means for securing the stencil can be designed in any other suitable way.

For the adjustment of the ink cloth an adjustment mem-- ber 22 is provided which is shown in section in FIG. 3. On its rear side the adjustment member is provided with two radially extending grooves 23 and 24 in which the -pins7 and 19, respectively, can be displaced. By a clockwise turning of the adjustment member the pin 19 is displaced to the right in FIG. 2 and the pin 7 to the left in Hereby the ink cloth can be made to take up theposition shown in FIG. 1. The adjustment member can be locked in the position in which it is set by locking members known per se,,e.g. a ball engaging depressions on the underside of the adjustment member or by means of a spring wire 30 formed on the adjustment member and engaging notches 32 in the carrying bar and extending below the periphery of the adjustment member.

1 The construction can be varied in many ways within the scope of the invention when only the main principle, viz. that the ink cloth is turned, is preserved. The advantage of the construction is that the stencil lies firmly on the ink cloth during the turning, and that one need not touch the stencil when once it has been placed in smooth contact against the ink cloth.

I claim: 7

1. A device for aligning a stencil in duplicating ma- 5 ed on said carrier, a rotatable adjustment member mounted on said transverse bar, pins at one end of said underlay engaging and controlled by said adjustment member to entail displacement of said pins to opposite sides of a longitudinal centre line through the axis of rotation of 10 said adjustment member.

2. A device as claimed in claim 1 wherein said adjustment member is provided with locking means for locking said adjustment member in the position wanted.

1 References Cited by the Examiner UNITED STATES PATENTS 798,800 9/1905 Klaber 101-116 1,730,122 10/1929 Busk 101415.1 20 1,790,407 1/1931 Creed 101116 X 2,189,682 2/1940 Schmutz 101-415.1 2,916,990 12/1959 Du Bois 101415.1 3,101,048 8/1963 Carlsen 101-125 3,151,554 10/1964 Townsend 101415.1

ROBERT E. PULFREY, Primary Examiner.

H. P. EWELL, Assistant Examiner. 

1. A DEVICE FOR ALIGNING A STENCIL IN DUPLICATING MACHINES COMPRISING A SUBSTANTIALLY RECTANGULAR INK-PENETRABLE UNDERLAY TO BE MOUNTED ON A CARRIER RUNNING IN A CLOSED PATH AROUND TWO ROLLERS, MEANS FOR MOUNTING A STENCIL ON SAID UNDERLAY, A TRANSVERSE CARRYING BAR MOUNTED ON SAID CARRIER, A ROTATABLE ADJUSTMENT MEMBER MOUNTED ON SAID TRANSVERSE BAR, PINS AT ONE END OF SAID UNDERLAY ENGAGING AND CONTROLLED BY SAID ADJUSTMENT MEMBER TO ENTAIL DISPLACEMENT OF SAID PINS TO OPPOSITE SIDES OF A LONGITUDINAL CENTRE LINE THROUGH THE AXIS OF ROTATION OF SAID ADJUSTMENT MEMBER. 